


I'll be your boyfriend

by itboyoikage



Category: Haikyuu!!
Genre: Fluff, M/M, Misunderstanding, No Smut, Post-Time Skip, Whipped Kageyama Tobio, whipped Oikawa Tooru
Language: English
Status: Completed
Published: 2020-10-08
Updated: 2020-10-08
Packaged: 2021-03-07 23:15:38
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,000
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/26895814
Author URL: https://archiveofourown.org/users/itboyoikage/pseuds/itboyoikage
Summary: "Oikawa-san, shut up or I'll rail you."Oikawa then smirked and with a smooth husky voice replied,"Rail me then, Tobio-chan."(Or an AU where Kageyama doesn't know what "shut up or I'll rail you" really means and uses the phrase while he's fighting with Oikawa to shut him up.)
Relationships: Kageyama Tobio/Oikawa Tooru
Comments: 29
Kudos: 204





	I'll be your boyfriend

**Author's Note:**

> Hello! This is my first time making a fic and posting it so I'm quite nervous. I've had this hc for a long time and it's been bugging me nonstop ever since. And coincidentally, I just had the free time to actually write it so I hope I gave Oikage justice!! I hope you like it as much as I do!

"Well if it isn't Tobio-chan." Oikawa's voice was dripping with sarcasm as he looked at Kageyama with what the latter associates as thinly veiled contempt. "Fancy meeting you here."

"Oi, Oikawa, stop teasing Kageyama." Iwaizumi scolded Oikawa for his childish behavior to which Oikawa answered with, "rude, Iwa-chan!"

Kageyama looked at Iwaizumi gratefully. Too exhausted to do anything else. As much as he loved seeing Oikawa after a long time of just messaging and calling one another, he just wanted to go to their bus and finally lie down and have some peace and quiet so he could rest his aching muscles. 

The Japan National Team played and won against France but lost against Argentina, where Oikawa plays, and to say that Kageyama is tired was an understatement. 

So Kageyama just stared at Oikawa, exasperated, and trudged to the door. But the latter didn't get the hint or simply didn't care because he stopped Kageyama. 

"Where do you think you're going, Tobio-chan?" Oikawa raised an eyebrow. Kageyama ignored the pounding of his heart as Oikawa stopped him from moving by taking his hand and pushing him back to his place. "Just because we won against you doesn't mean you get to be rude to your senpai!" 

"I'm not in the mood to fight right now, Oikawa-san." 

"I didn't come here to see you anyway." Oikawa scoffs and rolls his eyes at Tobio's questioning gaze. "Coach ordered me to ask your team if you want to ride with us since we're checked in at the same hotel anyway." 

Kageyama was about to refuse when Bokuto yelled, "Hey hey hey! We'd love to!" At that, he looked at Bokuto, bewildered. "Well, I overheard our coach talking about the bus breaking down and being unable to pick us up, so." Bokuto shrugged and his teammates nodded their heads and voiced their assent:

"It wouldn't be so bad!"

"I'm okay with that as long as we get home."

"We'd love that, Oikawa-san!" Hinata jumped and agreed with great enthusiasm, not seeming a bit tired even after hours of jumping around spiking balls. 

Kageyama sighed for the hundredth time, knowing that he can't disagree with everyone on his team. So he excused himself to go to the bathroom once everything had been decided.

Once he got to the bathroom, he washed his face and shook his head as he remembered the way Oikawa's hand felt on his arm. He hates the way Oikawa makes him feel. He's already an adult for god's sake, but just being in the same room with him clouds Kageyama's senses and messes with his mind. 

He's really got to stop his little infatuation on Oikawa. Kageyama knows that his huge crush on the latter resurfaced when he met Oikawa at the Olympics after several years of no communication whatsoever. Oikawa apologized to him after the first match against Japan and Argentina which led to Oikawa giving his number to Kageyama and asking for his in return, telling him that they're only doing so because they're "friendly rivals" and that Kageyama should only contact him when there's an emergency. But soon enough, one question led to another and resulted in the two talking regularly and inevitably getting closer.

But he also knew that it would only be fruitless because Oikawa still hates his guts and he's more than sure Oikawa's never looked at him in that way. 

So he took a deep breath, forcefully pushed down his feelings and went to the bus.

* * *

Kageyama is now convinced that the world is out to get him. When he went in the bus, he looked around and saw that the only seat available was next to Oikawa, who was having a heated discussion with another Argentinian player on the neighboring isle whether aliens were real or not. Kageyama glared at Hinata who was supposed to be his partner. He's now seated next to Atsumu, smiling mischievously at Kageyama and giving him a thumbs up. 

He will really beat Hinata's ass when they get back to the hotel. But that's an issue for another day. 

He was still looking for ways to stop his heart's erratic beating when Oikawa noticed him standing near the doorway and ordered him to sit down next to him because, "Tobio-chan, we're not gonna get home any faster if you're just standing there looking like an idiot." To which Kageyama grimaced and disagreed.

"Where's Iwaizumi-san?" Kageyama asked when he sat down next to Oikawa. 

"How should I know?" Oikawa answered, already looking bored as he picked on his nails.

_Dear god, why him?_

Kageyama took a deep breath and glared at Oikawa.

The latter sighed and answered, "he's already on the way to the hotel, saying that he has something important that he needed to do."

At that, the bus roared to life and began to leave the venue.

* * *

If there was one thing Kageyama found out about Oikawa in just the fifteen minutes (and counting) they spent with each other on the bus, it's that Oikawa never runs out of things to say. 

"Tobio-chan, do you believe in aliens?" 

"No. Now can I–"

"What? Are you kidding me?" Oikawa looked at Kageyama incredulously. He then begins to rattle off one by one the reasons why he believes that aliens exist, slapping Kageyama's arm and saying, "Tobio-chan, listen! This is the most interesting part!" when he notices Kageyama's attention drifting. Kageyama is seriously contemplating why he likes the guy so much. 

When Kageyama thinks he's finally done and tries to sleep, Oikawa once again looks at him with a questioning gaze and says, 

"Hey Tobio-chan," Oikawa's voice drops down to a whisper and motions for Kageyama to get closer, to which Kageyama acquiesces.

He sees more than hears Oikawa open his mouth. But instead of asking Kageyama a question or telling him a random fact, Oikawa blew on his ear, making Kageyama recoil at the sudden action. 

And when what happened finally sank into Kageyama, his ears turned red and his heart started beating rapidly. He was so sure that Oikawa could hear it. That everyone in the bus could hear it. But he pushed it down and turned to glare at Oikawa who looked pleased with what he did.

"Why would you do that, Oikawa-san?" Kageyama hissed, still feeling Oikawa's breath on his ear.

"Because you're my idiot kouhai." Oikawa stuck out his tongue.

"And you're still childish." Kageyama ignored the way his mind fixated on Oikawa's words. _My idiot kouhai._ Not _a_ kouhai. _His_ kouhai. 

"I may be childish but at least I won today!"

"...I won't dignify that with a response cause I'm not childish. And you should probably learn how to do that too." Kageyama smirked at Oikawa who looks like he's going to explode from all his pent up frustration.

"You're such a rude kouhai. I can't believe I put up with you this long!" 

Kageyama wanted to retort that they were only schoolmates in middle school and that he never put up with Kageyama even before, but Oikawa was already having a very one sided argument with him.

"Oikawa-san–"

"Let me finish, Tobio-chan–"

"How about–"

"No how about you stop being rude and start listening to me–" 

He was growing more frustrated by the second and Oikawa wasn't even looking at him or listening to him. Kageyama's limbs feel so heavy and he still hasn't gotten his rest. His patience is growing thinner as Oikawa's voice gets louder and Kageyama thinks he's had enough. 

"OIKAWA-SAN, SHUT UP OR I'LL RAIL YOU." 

Suddenly, everyone in the bus was silent. Oikawa whipped his head so fast Kageyama thinks he's going to have a whiplash and looked at him, taken aback by his words. Kageyama and Oikawa just stared at each other, the former noticing a blush rising through Oikawa's cheek and his ears turning red. Kageyama didn't know what he said that could've warranted that reaction from the older, so he just stared back, looking bewildered.

But Oikawa shook his head, regained his composure, and moved his head closer to Kageyama, their noses almost touching. Kageyama froze at the sudden proximity. He couldn't move any further since he's backed against the window, so he didn't have a choice but to look Oikawa in the eye and try to look unaffected. To which Kageyama found it really difficult to do given the situation they're in.

Oikawa then smirked. And with a smooth husky voice replied,

"Rail me then, Tobio-chan." 

If Kageyama wasn't confused before, he's sure as hell confused now. 

"Uh, why are you so willing to get hit with a train?"

At Tobio's response, everyone in the bus howled with laughter. Even Oikawa pulled back, looking completely dumbfounded. 

"Tell me, my idiot kouhai, Tobio-chan," Oikawa said as he scrutinized Kageyama. "What do you think 'railing' someone means and why do you think that it means someone wants to hit or get hit with a train." 

"Shut up, Oikawa-san. I'm not an idiot." Kageyama muttered, glaring at Oikawa. "I saw it on social media. They said that when you're frustrated at someone and want them to shut their mouth, you should tell them 'shut up or I'll rail you' and that would make the other person shut up immediately….

"...I thought it was a threat. Like, 'Shut up or I'll hit you with a train'.." Kageyama trailed, looking embarrassed when Oikawa looked at him blankly, his arms crossed. 

"Shoyou." 

"Yes, Oikawa-san!" Hinata peered at the two sitting in front of him, still shaking with laughter and eyes shining with amusement. 

"You do know what 'I'll rail you' means, don't you?"

"Of course!"

"Then would you mind educating this innocent friend of yours?"

Hinata let out a laugh, eyes crinkling as he looked at Kageyama. The latter looked at Hinata, eyes full of accusation and bewilderment because he still doesn't know what he said wrong.

"Yamayama, you idiot! 'Shut up or I'll rail you' means that you're telling Oikawa-san that he should shut up or you'll fuck him." Everyone once again roared in laughter at Kageyama's gobsmacked face. 

"Well, you're technically right, Tobio-kun! It's just that, you won't hit him with just any train because you'll hit him with _your_ train." Atsumu waggled his eyebrows at Kageyama.

At that, Kageyama sputtered, his face turning beet red which prompted another wave of laughter from his teammates. 

"I didn't mean it that way– I mean I do mean it that way after knowing what it meant but–" Kageyama stopped abruptly when he realized what he just said. And in front of Oikawa at that. 

He turned even redder and hid his face, at a loss for words. Not knowing how to face Oikawa. He just accidentally spilled his feelings for Oikawa. In front of his and Oikawa's team. He doesn't think it could get any worse than that. But then,

"You know," Oikawa spoke softly after a while. "As much as I love to know that you want to rail me, I would also love it if you asked me out on a date first." 

Kageyama turned to look at Oikawa's deep brown eyes, realizing how tender they now look gazing at Kageyama. 

"Would you like to be my boyfriend, Oikawa-san?" Kageyama's eyes widened as he blurted it out. He then turned away, not wanting to see what Oikawa's face looked like. "I- I didn't mean to say that– I mean I did but–"

"Do you ever shut up, Tobio-chan?"

Kageyama looked at Oikawa once again, opening his mouth to retort when the latter kissed him. Kageyama couldn't breathe. He felt like he was hallucinating because he never thought Oikawa would like to be near him, much less kiss him. However, it only took Kageyama a second when he kissed him back. His mind was on overdrive when Oikawa pulled back and with a soft smile said, 

"Yes."

Oikawa rolled his eyes at Kageyama's bewildered and dazed state and repeated what he said.

"Yes, Tobio-chan. I'll be your boyfriend."

**Author's Note:**

> That's the end of this oneshot! I didn't write any smut because sadly I'm still not that well versed with writing it. Or writing in general lmao! But thank you so much for reading! It means a whole lot <3


End file.
